METHOD FOR INJECTION MOLDING PLASTIC PARTS BY AN INJECTION MOLDING MACHINE

摘要

An injection molding method that includes: (a) fitting an injection molding machine with an injection mold defining one or more molding cavities, with at least one mold plate provided with one or more channels for circulation of a tempering medium, (b) providing a feed of plastic material, (c) heating the molding cavities by circulating through the channels a first tempering medium, (d) injecting plastic material into the closed heated mold to fill the molding cavities, (e) cooling the molding cavities of the filled closed injection mold until at least partly solidifying the molded plastic parts by circulating through the channels a second tempering medium, (f) opening the injection mold by parting the injector plate from the ejector plate, (g) ejecting the at least partly solidified molded plastic parts by actuation of ejector pins of the ejector plate, and (h) repeating the cycle of steps (c)-(g).

主权项

1. A method for injection molding plastic part(s) by means of an injection molding machine, wherein the method comprises the steps of:
(a) fitting the injection molding machine with an injection mold defining one or more molding cavities, the injection mold including an injector mold plate and a reciprocating ejector mold plate, wherein the back side of at least one of the mold plates is traversed, respectively, by one or more open channels that are made by milling or cutting the backside of the respective plate and that extend between an inlet and an outlet each through a free edge of a mold plate, wherein one or more of the open channels is first finally closed for circulation of a tempering medium once the mold plates are in place in the injection molding machine, (b) providing a feed of plastic material having a first temperature within the processing window of the plastic material, (c) heating at least the one or more molding cavities to a second temperature within the processing window of the plastic material and maintaining the injection mold in closed condition at said second temperature by circulating through the one or more channels a first tempering medium having a third temperature, (d) injecting plastic material having the first temperature into the closed heated mold at an injection pressure less than 100 kg/cm2 to fill the one or more molding cavities, (e) cooling at least the one or more molding cavities of the filled closed injection mold to a fourth temperature below the first temperature until at least partly solidification of the molded plastic part(s) inside the injection mold by circulating through the one or more channels a second tempering medium having a fifth temperature, (f) opening the injection mold by parting the injector plate from the ejector plate, (g) ejecting the at least partly solidified molded plastic part(s) by actuation of ejector pins of the ejector plate, and (h) repeating the cycle of steps (c)-(g) until the desired number of plastic parts are produced.